GB1287725A - Optical mark reading apparatus - Google Patents
Optical mark reading apparatusInfo
- Publication number
- GB1287725A GB1287725A GB4005/70A GB400570A GB1287725A GB 1287725 A GB1287725 A GB 1287725A GB 4005/70 A GB4005/70 A GB 4005/70A GB 400570 A GB400570 A GB 400570A GB 1287725 A GB1287725 A GB 1287725A
- Authority
- GB
- United Kingdom
- Prior art keywords
- signal
- background
- level
- mark
- card
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
- G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
- G06K7/10544—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation by scanning of the records by radiation in the optical part of the electromagnetic spectrum
- G06K7/10821—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation by scanning of the records by radiation in the optical part of the electromagnetic spectrum further details of bar or optical code scanning devices
- G06K7/10851—Circuits for pulse shaping, amplifying, eliminating noise signals, checking the function of the sensing device
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Electromagnetism (AREA)
- Artificial Intelligence (AREA)
- Toxicology (AREA)
- General Health & Medical Sciences (AREA)
- Health & Medical Sciences (AREA)
- Computer Vision & Pattern Recognition (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Length Measuring Devices By Optical Means (AREA)
- Conveying Record Carriers (AREA)
- Optical Recording Or Reproduction (AREA)
- Photometry And Measurement Of Optical Pulse Characteristics (AREA)
Abstract
1287725 Thresholding pulses INTERNATIONAL BUSINESS MACHINES CORP 27 Jan 1970 [7 Feb 1969] 4005/70 Heading H3T [Also in Division G4] In a photo-electric card reader a mark is indicated if the ratio of the reflectivity of the background, i.e. the unmarked card, to that of the mark is greater than a certain value. The card is driven by rollers over a linear array of phototransistors which read the card column by column. Each phototransistor (33, Fig. 2, not shown) detects light reflected from a respective row and passes a signal to input 48 of an amplifier giving an output at 50. When the output level represents the background a capacitor 54 is charged to this level. When a brief subsequent signal occurs, of lower amplitude than the background signal, capacitor 54 maintains the background signal level across resistor 56 and current flows in resistor 57. If the current in 57 is equal to or less than that in 56 the base current of transistor 58 falls to zero and the transistor turns off, a mark-indicating signal appearing at output 60. A second resistorcapacitor arrangement 66-68 provides a reject signal should a different reflectivity ratio be exceeded. Since the capacitors charge to the background level cards of different colours can be read without adjustment of the circuits, and the marks are correctly indicated in spite of slow variations of signal, e.g. due to supply voltage changes.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US79754469A | 1969-02-07 | 1969-02-07 |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1287725A true GB1287725A (en) | 1972-09-06 |
Family
ID=25171139
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB4005/70A Expired GB1287725A (en) | 1969-02-07 | 1970-01-27 | Optical mark reading apparatus |
Country Status (9)
Country | Link |
---|---|
US (1) | US3560751A (en) |
JP (1) | JPS4919925B1 (en) |
CA (1) | CA942887A (en) |
CH (1) | CH529384A (en) |
DE (1) | DE2004937C3 (en) |
FR (1) | FR2033861A5 (en) |
GB (1) | GB1287725A (en) |
NL (1) | NL165310C (en) |
SE (1) | SE357273B (en) |
Families Citing this family (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS4949250B1 (en) * | 1969-02-14 | 1974-12-26 | ||
US3708678A (en) * | 1970-10-30 | 1973-01-02 | Servo Corp | Variable threshold circuit |
US3646324A (en) * | 1970-11-10 | 1972-02-29 | Gte Sylvania Inc | Information-processing system |
US3706887A (en) * | 1971-03-04 | 1972-12-19 | Ibm | Optical card reader |
US3761725A (en) * | 1971-12-30 | 1973-09-25 | Texas Instruments Inc | Automatic tire identifier with threshold setting proportional to the received signals |
US3751639A (en) * | 1972-06-08 | 1973-08-07 | Raytheon Co | Card reader system |
US3813540A (en) * | 1973-03-26 | 1974-05-28 | Ncr | Circuit for measuring and evaluating optical radiation |
US3835332A (en) * | 1973-06-04 | 1974-09-10 | Eastman Kodak Co | Inspection apparatus for detecting defects in a web |
US3832577A (en) * | 1973-06-22 | 1974-08-27 | Ibm | Threshold extraction circuitry for noisy electric waveforms |
JPS5334977B2 (en) * | 1974-03-07 | 1978-09-25 | ||
US3949233A (en) * | 1974-08-15 | 1976-04-06 | Pitney-Bowes, Inc. | Hand held bar code reader with constant linear amplifier output |
US4243876A (en) * | 1979-07-25 | 1981-01-06 | Westinghouse Electric Corp. | Background light intensity compensation circuit for a line scan camera system |
US4373114A (en) * | 1979-08-06 | 1983-02-08 | Teletype Corporation | Method and means of reading punched data tape |
DE3213769A1 (en) * | 1982-04-14 | 1983-10-27 | Datronic Gesellschaft für Informationsverarbeitung mbH, 8902 Neusäß | METHOD FOR PRODUCING MICROFILMS AND MICROFILM PRODUCED IN SUCH A WAY |
IT1259645B (en) * | 1992-04-10 | 1996-03-25 | Solis Srl | METHOD FOR DETECTING THE DENSITY CHANGE OF A FABRIC AND DEVICE FOR ITS IMPLEMENTATION |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3189745A (en) * | 1961-10-27 | 1965-06-15 | Philco Corp | Photo-electric sensing circuit |
BE626298A (en) * | 1961-12-22 | |||
NL295016A (en) * | 1962-07-27 | |||
US3248553A (en) * | 1962-12-19 | 1966-04-26 | Ibm | Binary record photosensing apparatus |
US3395963A (en) * | 1965-11-15 | 1968-08-06 | Hewlett Packard Co | Optoelectric data readout device |
US3461303A (en) * | 1966-12-14 | 1969-08-12 | Ibm | Variable threshold amplifier with input divider circuit |
US3360635A (en) * | 1967-02-23 | 1967-12-26 | Digitronics Corp | Head for reading a perforated record medium |
-
1969
- 1969-02-07 US US797544A patent/US3560751A/en not_active Expired - Lifetime
-
1970
- 1970-01-27 GB GB4005/70A patent/GB1287725A/en not_active Expired
- 1970-01-28 CH CH120370A patent/CH529384A/en not_active IP Right Cessation
- 1970-01-28 CA CA073,283A patent/CA942887A/en not_active Expired
- 1970-02-03 FR FR7003615A patent/FR2033861A5/fr not_active Expired
- 1970-02-04 DE DE2004937A patent/DE2004937C3/en not_active Expired
- 1970-02-05 NL NL7001608.A patent/NL165310C/en not_active IP Right Cessation
- 1970-02-06 JP JP45010054A patent/JPS4919925B1/ja active Pending
- 1970-02-06 SE SE01562/70A patent/SE357273B/xx unknown
Also Published As
Publication number | Publication date |
---|---|
DE2004937B2 (en) | 1977-12-01 |
NL7001608A (en) | 1970-08-11 |
DE2004937A1 (en) | 1970-09-03 |
NL165310C (en) | 1981-03-16 |
FR2033861A5 (en) | 1970-12-04 |
JPS4919925B1 (en) | 1974-05-21 |
SE357273B (en) | 1973-06-18 |
CA942887A (en) | 1974-02-26 |
NL165310B (en) | 1980-10-15 |
CH529384A (en) | 1972-10-15 |
US3560751A (en) | 1971-02-02 |
DE2004937C3 (en) | 1978-08-03 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PS | Patent sealed [section 19, patents act 1949] | ||
PCNP | Patent ceased through non-payment of renewal fee |